package avltree;

public class AVLTreeDemo {
    public static void main(String[] args) {
        int arr[] = {10,11,7,6,8,9};
        AVLTree avlTree = new AVLTree();
        for(int i=0;i<arr.length;i++) {
            avlTree.add(new Node(arr[i]));
        }
        avlTree.infixOrder();
        System.out.println(avlTree.getRoot().height());
        System.out.println(avlTree.getRoot().leftHeight());
        System.out.println(avlTree.getRoot().rightHeight());

    }
}



class AVLTree{
    private Node root;

    public Node getRoot() {
        return root;
    }

    public void add(Node node) {
        if(root == null) {
            root = node;
        }else {
            root.add(node);
        }
    }
    public void infixOrder(){
        if(root == null) {
            System.out.println("该树为空~");
            return;
        }
        else {
            root.infixOrder();
        }
    }
    public Node search(int value){
        if(root == null) {
            return null;
        }else{
            return root.search(value);
        }
    }
    public Node searchParent(int value) {
        if(root == null) {
            return null;
        }else {
            return root.searchParent(value);
        }
    }
    public int delRightTreeMin(Node node) {
        Node target = node;
        while(target.left!=null) {
            target = target.left;
        }
        delNode(target.value);
        return target.value;
    }
    public int delLeftTreeMax(Node node) {
        while(node.right!=null) {
            node = node.right;
        }
        delNode(node.value);
        return node.value;
    }
    public void delNode(int value) {
        if(root == null) {
            return;
        }else {
            Node targetNode = search(value);
            if(targetNode == null){
                return;
            }
            if(root.left == null && root.right == null) {
                root = null;
                return;
            }

            Node parent = searchParent(value);
            if(targetNode.left == null && targetNode.right == null) {
                if(parent.left != null && parent.left.value == value) {
                    parent.left = null;
                } else if (parent.right!=null && parent.right.value == value) {
                    parent.right = null;
                }
            } else if (targetNode.left != null && targetNode.right != null) {
//                int minVal = delRightTreeMin(targetNode.right);
//                targetNode.value = minVal;
                int maxVal = delLeftTreeMax(targetNode.left);
                targetNode.value = maxVal;
            }else {
                if(targetNode.left!=null) {
                    if(parent != null) {
                        if (parent.left.value == value) {
                            parent.left = targetNode.left;
                        } else {
                            parent.right = targetNode.left;
                        }
                    }else {
                        root = targetNode.left;
                    }
                }else {
                    if(parent != null) {
                        if (parent.left.value == value) {
                            parent.left = targetNode.right;
                        } else {
                            parent.right = targetNode.right;
                        }
                    }else {
                        root = targetNode.right;
                    }
                }
            }
        }

    }
}
class Node{
    public int value;
    public Node left;
    public Node right;
    public Node(int value) {
        this.value = value;
    }

    @Override
    public String toString() {
        return "Node{" +
                "value=" + value +
                '}';
    }
    public int leftHeight() {
        if(left == null) {
            return 0;
        }
        return left.height();
    }
    public int rightHeight() {
        if(right == null){
            return 0;
        }
        return right.height();
    }
    public int height() {
        return Math.max(left == null ? 0 : left.height(),right == null ? 0 : right.height()) + 1;
    }
    public void leftRotate(){
        Node newNode = new Node(value);
        newNode.left = left;
        newNode.right = right.left;
        value = right.value;
        right = right.right;
        left = newNode;
    }
    public void rightRotate() {
        Node newNode = new Node(value);
        newNode.right = right;
        newNode.left = left.right;
        value = left.value;
        left = left.left;
        right = newNode;
    }
    public Node search(int value) {
        if(value == this.value) {
            return this;
        } else if (value < this.value) {
            if(this.left==null){
                return null;
            }
            return this.left.search(value);
        }else {
            if(this.right==null){
                return null;
            }
            return this.right.search(value);
        }
    }
    public Node searchParent(int value) {
        if((this.left!=null && this.left.value == value)||(this.right!=null && this.right.value == value)) {
            return this;
        } else {
            if(value<this.value&&this.left!=null) {
                return this.left.searchParent(value);
            } else if (value >= this.value && this.right != null) {
                return this.right.searchParent(value);
            }
            return null;
        }
    }
    public void add(Node node) {
        if(node == null)
            return;
        if(node.value < this.value){
            if(this.left == null) {
                this.left = node;
            }else {
                this.left.add(node);
            }
        }else {
            if(this.right == null) {
                this.right = node;
            }else {
                this.right.add(node);
            }
        }
        if(rightHeight() - leftHeight() > 1) {
            if(right!=null && right.leftHeight() > right.rightHeight()) {
                right.leftRotate();
                leftRotate();
            }else {
                leftRotate();
            }
            return;
        }
        if(leftHeight() - rightHeight() > 1) {
            if(left!=null && left.rightHeight()>left.leftHeight()){
                left.leftRotate();
                rightRotate();
            }else {
                rightRotate();
            }
        }



    }
    public void infixOrder(){
        if(this.left!=null){
            this.left.infixOrder();
        }
        System.out.println(this);
        if(this.right!=null){
            this.right.infixOrder();
        }
    }
}